1. Technical Field
The present invention relates to a power booting sequence control system and a control method thereof, more specifically to a power booting sequence control system and a control method thereof of each power switch of element blocks in an integrated circuit.
2. Background
The use of power gating to remove the power supply to portions of an integrated circuit is the most effective way to reduce leakage, as a method to further reduce power consumption by inactive circuitry. However, powering up circuitry can have various problems including dynamic IR drop, in-rush current and other problems than can lead to power loss or improper chip operation. Even more seriously, huge in-rush current may also result in on-chip low dropout (LDO) voltage regulators or some IPs can not work well. Therefore, the management of the power booting usually further design an on-chip power gating in the integrated circuit to control the open or close of the power switch of each element block in the integrated circuit.
Moreover, due to a need of low power consumption in many electronic products now, requirements for the power control of the integrated circuit are stricter, that is, the location and the time of each power switch in the controlled circuits are exacter than before. However, the way of power booting at present usually causes the in-rush current value too large and rising speed of the voltage not rapid enough in a state of sequentially turning on the power, and then causes many unexpected problems on the design of the integrated circuit; therefore, the performance of the integrated circuit is affected. Hence, a need of designing an ideal power booting sequence control system in an integrated circuit and a control method thereof is an urgent issue that can be applied to the business.